Electric cableway system.



w. DAY. ELECTRIC GABLEWAY SYSTEM.

, PATENTED JUNE 5,. 1906.

,APPLZGATIOH FILED JAN.6,1905.

' fine/760w:

Maxwefl 14/. Day. 7 by UNITED, STATES.

P TENT OFFICE.

M XWELL W. DAY, or SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A

CORPORATION or NEW YORK.

ELECTRIC CABLEWAY sYs rEM.

Specification of Letters Patent.

Patented June 5, 1906.

Application filed January 6, 1905. Serial No. 239,897.

T0 aZZ whom it may concern:

Be it known that I, MAXWELL W. DAY, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Electric Cableway Systems, of which the following isa specification.

The present invention relates to cableway systems in which the load or object to be moved along the cableway or track is actuated by means of a traveling cable which connects the sending and receiving stations and which is operated by means of power at one of the stations. v A

Where the system is employed for coaling ships at sea, one end of the system being supported upon the ship which is being supplied With coal and the other end being mounted upon the collier or sending station, the lurching of the ship or the ship and collier will cause the track and propelling-cable tosag sufficiently to bring them in contact with the water unless some preventive means is provided. In such cases the cable which forms the track or support is usually secured at one end to the towing vessel, while the other end passes over thetowed vessel and is attached to a sea-anchor, so that the track is maintained fairly taut even though the' ships may lurch or roll. It is not possible, however, to

prevent the propelling-cable from sagging by means similar to that employed in connection with the supportin -cabl e, for the reason that the propelling-cab e must be free to travel, so as to move the load between the two stations. Although a sagging of the propellingcable does not cause the load to drop mto the water, it nevertheless may bring the cable itself into contact with the water and may cause it to become fouled either with itself or with some part of the vessel or tow-rope. Various expedients have been adopted or suggested for maintaining a proper tension upon the propelling-cable, arnon them being the introduction-of friction-c utches between the drums at the ends of the cables andv the driving-motors. It has also been proposed to control the tension of the cable elecchine each end ofit 'e-cabl'ej' onelQfi-the,

*fromgeisource of, current-supply;

" the macl-i-in operating 5;

en tei i and supplying energy to of any character.

the cable of an ordinary cableway a pair of which the ends of the cable arewound, The motors are so connected to the source of cmrent-supply that they have a constant tendency to wind up the cable ends upon the respective drums. The controllin the motors is so organized that t e efforts of will, whereby one motor is caused to overcome the other, winding up the cable at one endiand unwinding it at the other end at which the motor exertin the least pull is sitmotion and when at rest.

Further objects of the present invention will appear in connection With the following description of one embodiment thereof,which is illustrated in the accompanying drawings, wherein Figure 1 illustrates two ships and a cableway spanning the s ace between them. Fig. 2' illustrates a cab eway system arranged in accordance with the present invention, and- Figs. 3 and 4 are details showing further modifications of the operating means for the cable.

1 Similar reference characters will be used throughout the specification and drawings to denote like parts.

Reference bein had to the drawings, A represents a shi a collier, and C a cable- Way extending etween the ship and collier. The cableway consists of the usual track or supporting-cable cand the cable 1, the ends of which are secured to drums or hoists 2 and 3, and which is supported at an intermediate point upon a sheayfieA ,suitahlymounted, as

To the above ends I have associated with uated. In this manner t ere is at all timesadefinite tension upon the cable,.both whenm use of clutches or complex control apparatus motors, which are connected to drums upon means for one or both of the motprs may be varied atthe motors wlllbe suppliedwith proper our- .the lines-L and I1. v the line L, I have arranged a rheostat or move it alongthe track. These parts may be of any usual or preferred t e, since they in themselves form no part of t e. present invention. The drums 2 and 3 are geared or otherwise connected to electric motors 7 and 8, respectively, these connections being preferably permanent in character, since no clutches or other loose driving means is required. and 11 and 12 the fields of the motors 7 and 8, respectively. The motors may be wound in any of the usual ways, since the articular kind of winding is immaterial, alt ough the series winding, as, illustrated, is referred. The motors are connected in ara lel across Between't 'e motors and.

rheostats, the system illustrated in Fig. 2 having a single rheostat 13 common toboth motors. The arm 14 of the rheostat is electrically connected to line L and is adapted to pass over and engage with the contacts 15, associated with the sections of the rheostat. When the arm 14 is in the position shown, an equal portion of the rheostat is in series with each of the armatures, and therefore if the parts are properly constructed and arranged rents to give equal torques. The arrangement of parts is such that the current in passing through the motors tends at all times to drive them in the direction to wind up the ends of the cables on the drums or hoists 2 and 3.

It'is evident that when the arm 14 of the rheostat is in a neutral position the tendency of both motors will be to Wind up the ends of the cable upon their'respective drums; but since the torques of the two motors are .e ual no movement of the cable will result un ess the tension of the cable is less than the pull exerted by the motors, and if the cable tension is less than such ull then the ends of the cable will be woun upon the drum until the pull of the motors is just balanced.

It is further evident that if the ships lurch or if for an reason the distance between the sheave an the drums decreases the motors, although normally at rest, will immediately take up the slack 1n the cable until the proper tension is obtained. Similarly, if the lurching of the vessels is such that the distance between the sheave and the winding-drum increases the ends of the cable sim 1y unwind themselves from their respective rums, pulling the motors with them; In this manner perfect control is obtained over the cable when it is at rest'that .is, when it is not traveling with its load.

If the arm 14 of the rheostat is moved shghtl to the left, the resistance in the circmt w ch includes motor 7 is less than that in the circuit which includes motor 8, and

therefore a greater amount of current will be supphed to the motor 7, causing motor 7 to 9 and 10 are the motor-armatures,.

exert a greater pull upon the adjacent end of the cab e than that which motor 8 is able to exert u on the other end of the cable. As a result t e cable will be wound upon drum 2 and will be unwound from drum 3, themotor 7 pulling the motor 8 backward against the tendency of thelatter motor to rotate in a forward direction-that is, in a direction to wind up the cable upon the drum 3. In this way a definite tension may be placed upon the cable and maintained notwithstanding lurching of the ships, for the reason that if ships lurch toward each other, slackening the cable, the motor 8 will immediately follow its normal tendency and will wind u the cable upon the drum 3 until the norma tension is again reached, whereupon the ull of the motor 7 again comes upon the ot er motor and unwinds the cable from drum 3. As the arm 14 is moved toward its extreme position on the left-hand side the speed of the motors is increased; but the tension upon the cable does not necessarily increase, since the current supplied to motor 8 is weakened, due to the cutting in of the additional resistance.

Assuming that the movement of the cable upon turning the rheostat-arm to the left draws in the bucket or load, it is clear that a movement of the-rheostat-arm to the right produces a reverse movement of the cable by reason of the motor 8 pulling the motor 7 backward, and thereby causing the bucket or load to be moved in the opposite direction. Upon returning the rheostat-arm to the neutral position the bucket or load may be stopped at either the sending or receiving stations or at any intermediate point. Main switches may of course be employed for shutting off the current entirely when the apparatus is not in use. The present system consequently afl'ords means-tor controlling the movement and the tension of the cable in a simple and eflective manner and in a manner which requires little attention or manipulation on the part of the operator, since it is only necessary in order to start the load in one direction or the other to move the rheostat-arm to the right or to the left and vto bring it again to the neutral position when it is desired to bring the load to rest.

In F ig. 3 I have shown a motor provided with a separate rheostat, the rheostat 13 bemg assoclate'd with the motor 8 and the rheostat 13 being associated with the motor 7.

The contacts of these two rheostats may be arranged concentricalli or in any other symmetrical manner, so t at a sin le arm 14,- corresponding to the arm 14 of ig. 2, serves to cut resistance into one motor-circuit and simultaneously remove resistance from the circuit of the other motor.

In Fig. 4 the rheostats 13 and 13 areshown as arranged independently of each.

other, each having its own arm 14 and 14, respectively, these arms being either connected to each other or independent of each other, and if they are independent then a wider range of variations may be obtained than in. the other modifications, for the reason that the current supplied to one motor need not be decreased as the current passing through the other motor is increased. Even if the arms 14* and 14 are entirely independent of each other the controllin mechanism does not become objectionabIy complex, since it is only necessary for the operatorto actuate two handles which operation does not require particular careor skill and but little time.

In all the forms of the present invention illustrated clutches. and complex mechanisms of all kinds are dispensed with, and the arrangement of the parts is such that there is very little mechanism which is apt to get out of order or which requires delicate adjustment and careful attention in order to enable it to erform its roper functions.

W ile I have described the present invention with great particularity as embodied in some of its various forms, I do not desire to limit the present invention to the particular vform illustrated and described, since in its broader aspects manv other modifications may be made in addition to those illustrated without departing from the spirit and scope of the invention as set forth in the appended claims What I claim as new, and desire to secure by Letters Patent of the United States, is

. 1. In a cableway system, a cable, means for driving the cable, and means for'maintaining a tension upon said cable both when moving and when at rest.

2. In a cableway system, a cable, and electrical means for driving the cable and for maintaining a tension thereon both when the cable is moving and when at rest. 1

3. In a cablewa system, a cable, a pair of motors associate therewith and permanently connected to a source of current-supply in such a manner that the motors tend to wind up the ends of the cable, and means for varying the proportion of the whole'current which each motor receives. l

4. In a cableway system, a cable, a pair of motors associated with the ends of the cable for Winding up the same, means for supply ing said motors continuously with current tending to rotate the motors to wind the cable, and means for varyin the relative strength of the currents supplled to each motor. I

5.. In a cablewaysystem, a cable, a pair of motors connected in parallel to a source of current-supply and connected to the ends of the cable for winding up the same, resistances located in the connection between the motors and said source of current-supply, and means for varying the pro ortion of the resistance which is in series wit each motor.

6. In a cableway system, a cable, a pair of motors one terminal of each of which is con-- nected to a correspondin terminal of, a series of resistance-sections an the other terminals of which are connected to one terminal of a source of current-supply, and a movable member cooperating with contacts associated with said resistance-sections and electrically connected to the other terminal of said source "of current-supply. said motors being connected to the ends of the cable for winding up the same when the motors are operated.

7. In a cableway system, a cable, a pair of motors assoclated with 0 posite ends of the cable 'and'arranged to pull in opposite directions u on the cable, and means for varying the pu which one of the motors exerts.

8. In a cableway system, a cable, a pair of motors associated-with o posite ends of the cable and arranged to pull in opposite direc tionsupon thercable and means for varying the effective pull of each motor.

9. In a cableway system, a cable, a pair of motors connected with opposite ends of the cable, and a controller constructed and arranged to supply current to the motors so as to cause the motors to operate similarly at each end of the cable.

In witness whereof I have hereunto set my hand this 4th dayof January, 1905.

. MAXWELL W; DAY. Witnesses:

BENJAMIN B. HULIL,

HELEN ORroRD. 

